//登陆验证
module.exports =( username, password ) => { 
    let ret = { flag: true, msg: [] };
    if ( '' == username ) { 
        flag = false;
        ret.msg.push('账号不能为空')
    }
    if ( '' == password ) { 
        flag = false;
        ret.msg.push('密码不能为空')
    }
    return ret;
};